Pipe-wrench.



H. F. HOFPMANN.

PIPE WRENUH.

APPLICATION FILED MAR.12, 1913. 1 070 343 Patented Aug. 12, 1913.

i2 /lf 1 T2 (@(Vlgai U 1 l7 I I l2 v WIT/V58 E8 INVENTOR Henry F Hofi mann,

I I I M ATTORNEYS COLUMBIA FLANOGRAPH 60.. WASHINGTON, D. c,

HENRY r. HOFFMANN', OF NEW YORK, N. Y.

PIPE-WRENCH.

Specification of Letters Patent.

Application filed March 12, 1913.

Patented Au 12, 1913. Serial No. 753,732.

To all whom it may concern Be it known that I, HENRY F. HOFFMANN, a citizen of the United States, and a resident of the city of New York, Stapleton, borough of Richmond, in the county of Richmond and State of New York, have-invented a new and Improved Pipe Wrench, of which the following is a full, clear, and exact description.

This invention relates to pipe wrenches of the type covered by Letters Patent of the United States, No. 834,807, issued to me on October 30, 1906.

Among the objects of the present invention is to improve this class of wrenches whereby they are made more easily adjustable by one hand operation.

A further object of the invention is to increase the facility or speed of adjustment to fit various sizes of work, the adjustment being effected during the transfer of the wrench from one part of a machine to another without the loss of a moment of time.

A still further object of the invention is to so construct a wrench of this character as to make it more compact and thereby enable the operator to have access to narrower spaces for operation than heretofore, and at the same time provide a construction having the maximum strength in proportion to its mass.

A still further object of the invention is to provide a simple and effective means to lock the movable jaw in any position of adjustment so that when the wrench is laid aside temporarily, the same adjustment may be maintained, and also to provide for the making of the movable jaw substantially rigid when operating upon nuts or the like in either direction.

The foregoing and other objects of the invention will hereinafter be more fully described and claimed and illustrated in the drawings forming a part of this specification in which like characters of reference indicate corresponding parts in all the views, and in which Figure 1 is a side view, parts being in section, of a preferred embodiment of the invention, this figure illustrating the position of the operators hand when releasing the ratchet mechanism for outward adjustment of the movable jaw; Fig. 2 is a side view showing, in dotted lines, the position of the hand and relativepositions of parts of the wrench when moving the outer jaw into engagement with the work, and showing in full lines the positionof the hand when releasing the movable jaw from the work; Fig. 3 is an edge view of the wrench; Fig. 4 is a plan view of the blank from which the yoke is made; and Fig. 5 is a detail of the lock above referred to.

Referring more particularly to the drawings, I show at 10 an inner or stationary jaw to which is connected, preferably integrally, a handle 11. At the rear and inner portions of the jaw 10 on opposite sides of the handle 11 are formed a pair of concave shoulders 12.

The numeral 13 indicates an outer or movable jaw having an inwardly projecting shank 14, the extreme inner end thereof having a rearwardly projecting hook 155. Said jaws are preferably provided with teeth or serrations 10 and 13 respectively of any suitable configuration for gripping purposes.

The movable jaw is connected for cooperation with the stationary jaw by suitable ratchet connection whereby the movable jaw will be maintained in adjusted position automatically, said mechanism being of such a character that the operator, while holding the wrench in one hand, may release the ratchet mechanism so as to allow the movable jaw to drop or glide downwardly or outwardly by gravity. Said ratchet mechanism in its preferred form comprises a yoke 16 embodying a pair of side plate 17 connected across the front of the handle by a strap 18. The side plates are provided with hubs 19 which cooperate with the concave shoulders 12, the yoke being pivoted permanently to the handle by means of a pivot 20, the axis of which is at the center of curvature of said shoulders. By virtue of this construction or cooperation between the yoke and the f inner jaw, the strain of the outer jaw, when force is applied to the wrench, will be borne directly between the hubs 19 and said shoulders. The form of yoke herein set forth is such that the total width or thickness of the tool, as shown in Fig. 3, is preferably not greater than the width of the jaws, whereby it is expedient to use this wrench in places not accessible with other wrenches. Furthermore, the strap 18 embracing the handle 11 constitutes an effective reinforcement for the yoke, whereby this wrench possesses superior strength in resistingside strains, it being a well known fact'thatwrenches in general, including certain. types of pipe wrenches, are deficient in this regard. I also show at 18 an auxiliary brace which is secured to the side plates 17 andoperates between the shank 14 and the handle 11 during the pivotal movements of the yoke. Said brace 18 may be in the nature of a. screw fixed as indicated, and may be used either separately or in. connection with the strap or brace 18. I also show a pair of ears 12 extending upwardly from the shoulders 12 or as extensions of'the inner jaw and adaptedto embrace the shank 1a to further strengthen the wrench to prevent breakage or distortion of the same when subjected to lateral strains.

As in my previous patent, the means for preventing unintentional outward movement of the aw 13 consists of a toothed block 21 rigidly connected to and between the rear ends oftheside plates 17 as by countersunk rivets 22. Said block and rivets consti tutea strong cross brace for the rear end of the yoke, and a rivet 23 constitutes a correspending brace for theintermediate portion theneof between the shank and the handle 11-. The teeth 21 of the block cooperate with corresponding-teeth1st of the shank 1st and are preferably of a comparatively small size for delicacy of adjustment. Since, however, the face of the block having the teeth 21" is substantially straight and cooperates with a comparatively large portion of the shank let, the strength of the ratchet mechanism is reliable.

The'innerend of, the block 21 is extended to formal tailpiece-24c whereby, upon appli cation of the thumb, as shown in Fig. 1, in the direction ofthe arrow at, the yoke is caused to swing: around the axis of the pivot 20 and the teeth 21' are released from the teeth 14, it being noted that the teeth 21 are located substantially outward of said axis, while the tail piece 24: is extended inward with respect tosaid axis. Normal cooperation between the block 21 and the toothed shank 14 is effected by any suitable automatic means such asav spring 25 shown as a: leaf spring connected at its inner end to the rear edge of the handle and having its outer free end bearing against the front sideof therivet 23 or between said rivet and the rear edge of the handle. The normal tendency, therefore, of this spring is to cause the block 21 to swing outwardly around the axis of the pivot 20 into engagement with theteeth. 14. The pressure of the thumb, asshown in Fig. 1, is superior to-the force of the spring 25, and when'the thumb is so applied, the movable jaw and its shank 1 1 are free to dropoutward to any desired distance, said. movement being limited, however, by thepin 26 at the inner end of the shank which isadapted to contact with the inner edge of either or both of the side plates 17.

After the movable jaw is thrown or dropped outward as suggested in Fig. l, the next step is for the operator to shift the thumb into the concavity of the hook as shown in dotted lines in Fig. 2, when, by holding the handle of the wrench with his fingers, he will drag, in the direction of the arrow 7), the movable jaw inwardly into contact with the work IV. Ilpon releasing the thumb, therefore, from the hook, the spring 25 will serve to cause the movable jaw to retain its griptemporarily upon the work and then by applying force to the wrench in the usual way said grip will be augmented and made practically positive as is usual in this type of wrenches. No matter, however, how much force may be applied to the wrench during its usual operation, the movable jaw may be freed from the work by the simple applicationof the thumb to the end of the hook, as shown in full lines in Fig. 2, in the direction of the arrow 0.

The hook 15 is shown made preferably of a. separate part and pivoted at 15 to the inner end of the shank 1 1. This constitutes a. locking member including a point 15 nested normally within the end of the shank and so maintained by the friction at the joint. As shown in dotted lines in Fig. 1, the hook 15, while normally extended as shown in full lines, is adapted tobe turned on the pivot so as to cause the point 15 to engage the spring 25 and thereby prevent suiiicient pivotal movement of the yoke and shank as will make it possible for the movable aw to be changed in its adjustment while the lock is so set. Fig. 5 shows in full lines this feature. A mechanic, for eX- ample, having used the wrench upon a certain size of pipe, and wishing to preserve the adjustment while the wrench is momentarily laid aside, will turn the lock into the position shown in Fig. 5 and by dotted lines in Fig.

1. Another advantage of this lock is to make the pivotally mounted movable jaw of a pipe wrench substantially rigid so that the two jaws will cooperate with a nut for rotation in either direction very similar to the operation of an ordinary monkey wrench.

The several parts of this wrench may be made of any suitable materials, but I suggest that the yoke and its block be made of steel. and the shank ll of the outer jaw of a softer material for a more satisfactory cooperation between the two sets of ratchet teeth. Furthermore, the precise design or relative proportions of the parts may be varied to a certain extent without departing from the spirit of the invention hereinafter claimed.

Having thus described my invention, I claim as new and desire to secure by LettersPatent:-

1. In a wrench, the combination of a stationary aw, a handle secured thereto, a jaw movable toward and from the stationary jaw, a shank connected to the movable jaw and extending inwardlv therefrom adjacent said handle, a rearwardlv extending hook attached to the inner end of the shank whereby the movable jaw and shank may be manipulated by the hand holding the wrench, and automatic ratchet mechanism tending to secure the movable jaw in cooperative relation with said stationary jaw.

2. The herein described pipe wrench comprising, in combination, a stationary jaw, a handle extending inwardly therefrom, a movable jaw, a shank extending inwardly therefrom parallel to the handle, said shank being provided along its rear edge with ratchet teeth, a leaf spring secured to the rear edge of the handle and extending between the handle and said shank, a hook pivoted to the inner end of the shank and serving as a thumb piece for the manipulation of the movable jaw in one position, said hook having an extension adapted to be turned in a direction substantially normal to the handle and serving as a lock for the movable aw in another position, and a yoke pivoted to the stationary jaw, said yoke embracing the handle and said shank and carrying a block having ratchet teeth coopcrating with said shank teeth, said yoke also including a transverse brace through which the spring operates upon the shank of the movable 3. In a quick adjustment pipe wrench, the combination of three principal relatively movable parts, namely, a stationary jaw and a handle extending inwardly therefrom; a movable jaw and a shank extending inwardly therefrom past the stationary jaw, and a yoke pivoted to the stationary jaw and embracing said handle and shank, a leaf spring secured to the handle and extending between the same and the shank, said spring cooperating with the yoke to control certain movements of the yoke and movable jaw, and a locking device pivoted to the inner end of the shank and serving in one position as a hook through which the movable jaw is adjusted inwardly, and adapted in another position to bear against said spring and lock the movable jaw and yoke from operation.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

HENRY F. HOFFMANN.

Witnesses: v

Gno. L. BEELER, PHILIP D. RoLLHAUs.

Copies of this patent may be obtained for five cents each, by addressing the "Commissioner of Patents, Washington, D. C. 

